Pedestrian detection devices are known to detect conditions of the presence or absence of pedestrians who are waiting for crossing roads or currently crossing the roads (refer to Japanese Patent Unexamined Publication No. 2002-024986). A pedestrian detection device disclosed in Japanese Patent Unexamined Publication No. 2002-024986 detects pedestrians present around an intersection using a stereo camera and updates a pedestrian management table in accordance with pedestrian tracking results obtained by tracking coordinates indicating the presence of each pedestrian in a time series.
When a large number of pedestrians are present, the amount of data processed in a time series increases, which may increase the workload of the device upon calculation.